Gas safety valve



A. R. HANSON 2,5293% GAS SAFETY VALVE Filed March 7, 1947 4 Illl NEWER Patented Nov. 14, 1950 UNITED STATES PATENT OFFICEAHI,

Andrew It. Hanson, Oklahoma City,v Okla.

Application March 7, 1947, Serial No. 733,119

Claims.

This invention pertains to an automatic cutoff valve intended primaril to control the flow of gas or the like.

The object of the invention is the provision of a valve which will automatically cut off the flow of gas when a reduction of pressure, due to a leak in the line, occurs. I

A further object of the invention is the provision of a valve which will automatically cut oil the flow of gas in the event of a shock of considerable magnitude such as in the event of an explosion or earthquake.

A still further object of the invention is the provision of a valve which will automatically cut off the gas flow should the pressure in the line pass a predetermined high.

With the above and other objects in view, which will appear from the following description, theinvention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed.

It is to be understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

The invention is illustrated by a single vertical sectional view through the valve in its closed or off position.

Describing the invention in detail with reference to the drawing, A is a casing having therein an inlet conduit I communicating with an inlet chamber 2 having an open upper end which is closed by a removable cap or plug 3. This cap is provided on its top with a boss 4 having a bore 5 provided at its upper end with a passageway 5a communicating with a transverse passageway 6 which communicates with the atmosphere.

A check valve I, disposed within the bore 5, normally rests upon a suitable support 8, leaving the passageway Be open, but is vertically movable to close the passageway.

The lower end 9 of the cap is hollow to provide a cylinder l0 having a lower open end and an upper end which is in communication with the bore 5. A hollow elongated tubular piston B is reciprocal in the cylinder and is provided with an upper end I I. Intermediate its length the piston is provided with a. main cut-off valve I2 the lower face of which seats upon the conical valve seat I3 at the upper end of the passageway I4 through the bottom of the inlet chamber 2 The lower end of the piston, beyond the valve I2, extends through the passageway and into the 2. outlet chamber I6 which has free communication with the outlet conduit I'I. y

The piston being hollow provides a internal chamber Is for the reception of a reciprocable check valve I9 having a lower conical end 20 which normally closes the passageway 2] through the lower end of the piston, The upper end 'of the piston chamber I8 is provided with a passageway 22.

The chamber bottom is provided internally with a boss 23 and externall with an opposed boss 24. A push rod 25 passes through these bosses and at its inner end within the outlet chamber is provided with a head 26 disposed in alignment with the lower end l5 of the piston B. The outer end 21 of the rod is enclosed by a removable cap 28.

The upper face of the valve I2 is provided with a circumferential flange or lip 29'to provide a valve which is adapted, as will hereafter appear, to seat against the lower end face of the lower end 9 of the cap 3.

When the valve lip 29 is in engagement with the cap end 9 the top face of the valve I2, that is the face portion inside the lip, is in communication with the cylinder I0 through the passageway 38 in the side of the piston B. The communication is through the piston chamber I8 and the passageway 22 in the top thereof.

Operation of the valve is as follows.

With gas flowing into the inlet chamber 2 through the inlet conduit I, the cap 28 is removed and by pushing upward on the rod 21 the valve I2 is elevated until its upper valve face 29 makes gas tight engagement with the lower end 9 of the cap 3. The check valve I is open and the check valve' I9 is closed. The valve I2 remains elevated because the pressure of gas to which the lower surface or face of the valve is subjected overcomes the force of gravity and also atmospheric pressure which is the only pressure which reaches the upper surfaces of the valve and piston.

Should there be any appreciable leak in the gas outlet line the gas pressure would fall to a point where the weight of the valve and its associated parts would cause the piston and valve l2 to move downward, to the position shown in the drawing, and close the passagewa l4. Gas supply to the outlet line would thus be cut off.

Provision is also made for automatically cutting off the gas supply to the outlet line in the event of a shock of considerable magnitude. Such a shock would cause the valve I2 to vibrate thereby permitting gas to pass the upper valve lip 29. This gas would pass through the passageway 30 into the piston chamber I8 and from it through the passageway 22 into the cylinder [0. The pressure of this gas would act upon the check valve 1 and cause it to move to a closed position in respect to the passageway a. Thus, pressure on the upper and lower sides of the valve [2 would be equalized and the valve would drop by gravity to a closed position on its seat l3.

A dangerously high pressure in the line may be objectionable and dangerous and provision is made to cut ofi the gas in the outlet line should this condition arise. The check valve I9 is designed to remain closed only so long as the gas pressure is below a predetermined high. When this pressure is exceeded the check valve 19 is lifted thus opening the passageway 2| and letting gas into the piston chamber. This gas pressure operates upon and closes the check valve 1 and also passes outward through the passageway 30 above the valve [2. The pressure above and below the valve l2 becomes equalized and the valve drops by gravity to a closed position.

I claim:

1. A device of the character described comprising, a casing having a gas conduit therethrough provided intermediate its length with a passageway having a valve seat, a member above said valve seat comprising a cylinder the upper end of which is provided with an outlet communicating with the atmosphere, an upwardly and outwardly closing check valve adapted to close said outlet, a hollow elongated tubular piston in said cylinder, a main disc-like cut-ofi valve carried by said piston external of the cylinder and adapted on downward movement to close the passageway in the conduit and on upward movement to seat in gas-tight engagement against the lower end of the piston communicating with the cylinder, said piston provided with a passageway positioned immediately above the cut-oil valve and communicating with the space between said valve and the lower end of the cylinder when the main cut-off valve is in engagement with the cylinder end, and means in the form of a manually operable lifter for moving the main cut-oif valve to the aforesaid fully elevated position.

Number 2. A construction as defined in claim 1 wherein, the lower external end of the piston is provided with an inlet passageway, a vertically movable check valve in said piston and in response to gravity normally closing said inlet passageway, and said valve when in an open position permitting the flow of gas from the conduit into the hollow piston for escape therefrom.

3. A construction as defined in claim 1 wherein, the lifter is in the form of a rod having one end within the conduit and alignment with the lower end of the piston and its other end positioned external of the casing, and a removable cap enclosing the external end of said rod.

4. A construction as defined in claim 1 wherein, the piston is of sufficient length at its lower end and extends through and beyond the conduit passageway when the main cut-off valve is in a closed position.

5. A device of the character described comprising, a casing having a gas conduit therethrough, a member at the top of the casing provided with a cylinder communicating with the atmosphere through an outlet passageway, an outwardly closing check valve adapted to close said passageway, a hollow elongated piston in said cylinder having its interior in communication with the cylinder, a main cut-off valve carried by the piston, the under side of said valve being adapted to cut oil gas fiow through the casing conduit, the upper side of the main cutoff valve being adapted to have gas-tight abutment with the inner lower end of the cylinder, the piston having a passageway positioned in its side wall immediately above the top of the main cut-off valve, and a manually operable lifter for moving the upper side of the main cut-off valve into engagement with the cylinder end.

ANDREW R. HANSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Baten Jan. 5, 1932 Hanson Jan. 14, 1941 

